1. Field of the Invention
The present invention relates to a navigation apparatus, and more particularly to a navigation apparatus for vehicles capable of sensing the peripheral situation of the vehicle, thereby automatically displaying the sensed peripheral situation on a monitor while generating an alarm when the peripheral situation is determined as a hazardous situation. The present invention also relates to a method for controlling such a navigation apparatus.
2. Description of the Related Art
By virtue of developments of the electronic industry, a navigation apparatus has been incorporated in vehicles, such as sea vessels, airplanes automobiles, etc. The driver/pilot can obtain navigational information from the navigation apparatus, including the vehicle's current position, so that the driver/pilot can accurately and rapidly reach the destination. Such a navigation apparatus is generally referred to as a GPS (Global position system), and is adapted to identify the current position and moving speed of the vehicle or to determine a movement path of the vehicle.
Such a GPS apparatus receives information, indicative of the latitude, longitude and altitude associated with the current position of the vehicle, from a plurality of GPS satellites, thereby computing the current position of the vehicle. After the computation, the GPS apparatus provides map information including the current position of the vehicle in the form of a graphic display. In other words, such a conventional navigation apparatus indicates on a display the current position of the vehicle, as calculated based on the information received from the GPS satellites.
The navigation apparatus also indicates the advancing direction and speed of the vehicle, the distance to an indicated destination, a path set by the driver prior to embarking on the trip, and an optimum path leading from the current position to the indicated destination.
However, due to gradual worsening of traffic conditions, it is sometimes difficult to drive even when the above-mentioned navigation apparatus is incorporated in the vehicle. For instance, parking spaces are insufficient in spite of an increase in the demand for vehicles. Additionally road layouts become more complex in accordance with the increased number of vehicles and roads. As the numbers of vehicles increases, the possibility of contact between vehicles also increases. In other words, the probability of accidents increases correspondingly. Such contact accidents occur frequently when it is difficult to recognize the peripheral situation as in the case when a vehicle starts to move or is being parked. In particular, it is difficult for drivers to locate persons or other vehicles existing in a blind spot. For this reason, there is a concern about accidents and hazards to human lives.
In order to solve the above-mentioned problems, a navigation apparatus has been proposed which is adapted to sense whether or not there is an object approaching the vehicle, and to show the sensed object to the driver of the vehicle. Such a navigation apparatus is disclosed in Korean Patent Application No. 95-56570 filed on Dec. 26, 1995 in the name of the assignee, SAMSUNG Electronics Co, Ltd.
In the case of the above-mentioned pending application, the position of an object existing in the vicinity of the vehicle is sensed by an infrared sensor. The distance between the object and the vehicle is also calculated. Based on the results of the sensing and calculating operations, the object is shown on a display unit in the form of a two-dimensional graphic display. However, it is very difficult to determine peripheral situations above and beneath the vehicle because the sensed object is shown in the form of a two-dimensional graphic display. Since the technique disclosed in the pending application only provides a function of simply showing the peripheral situations of the vehicle, it is difficult to determine the degree of hazard which may cause contact of the vehicles with peripheral objects.
Moreover, while it may be relatively easy to determine the direction of the wheels while the vehicles is in motion, it is sometimes impossible to determine the position of the wheels when the car is not in motion. This is especially the case when the car has been parked. In this case, it is difficult for the driver to determine the correct steering position of the steering wheel.